Self-tensioning vascular occlusion device and method for its use

ABSTRACT

The present invention advantageously provides self-tensioning occlusion devices, systems, and methods for percutaneous access and closure of vascular puncture sites. One device includes a catheter body, an occlusion member, and a tensioning member. The occlusion member, such an expansible member, is disposed on a distal end of the body. The tensioning member, such as a spring or coil, is slidably disposed over the body and proximal the expansion member. Generally, during application, the tensioning member will be deployed against subcutaneous tissue so as to apply tension to the expansible member against the puncture site. The substantial hold once the tension is applied is then provided by an external element, such as an anchoring clip.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation-in-part of and claims thebenefit of priority from U.S. patent application Ser. No. 10/857,177,filed on May 27, 2004, now U.S. Pat. No. 7,572,274, the full disclosureof which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to devices, systems, and methodsfor percutaneous sealing of puncture sites in body lumens or tissuetracts. More specifically, the present invention relates toself-tensioning vascular occlusion devices, systems, and methods for itsuse for hemostasis of vascular puncture sites.

Percutaneous access of blood vessels in the human body is routinelyperformed for diagnostics or interventional procedures such as coronaryand peripheral angiography, angioplasty, atherectomies, placement ofvascular stents, coronary retroperfusion and retroinfusion, cerebralangiograms, treatment of strokes, cerebral aneurysms, and the like.Patients undergoing these procedures are often treated withanti-coagulants such as heparin, thrombolytics, and the like, which makethe closure and hemostasis process of the puncture site in the vesselwall at the completion of such catheterization procedures more difficultto achieve.

Various devices have been introduced to provide hemostasis, however nonehave been entirely successful. Some devices utilize collagen or otherbiological plugs to seal the puncture site. Alternatively, suturesand/or staples have also been applied to close the puncture site.External foreign objects such as plugs, sutures, or staples however maycause tissue reaction, inflammation, and/or infection as they all “leavesomething behind” to achieve hemostasis.

There is also another class of devices that use the body's own naturalmechanism to achieve hemostasis wherein no foreign objects are leftbehind. Such devices typically provide hemostasis by sealing thepuncture site from the inside of the vessel wall wherein the device isleft in place in the vessel lumen until hemostasis is reached andthereafter removed. These devices generally comprises two separate anddistinct components, namely a catheter and an external tensioningelement. The external tensioning element is typically connected to thecatheter shaft and rests on an exterior surface of the skin after thecatheter is positioned in the vessel. It provides tension to thecatheter at the puncture site as well as anchors the applied tension sothat a tip of the deployed catheter is maintained against the vesselwall at the puncture site. The external tensioning element is kept intension for a period of time.

Although such devices have achieved relative levels of success, theexternal tensioning element is not always easy and convenient in itsapplication. Further, the external tensioning element may not alwayspreserve the integrity of the catheter system. For example, manipulationof the catheter when the external tensioner is applied or removed maycause disruption of the seal at the vessel puncture site, resulting inbleeding or hematoma formation (i.e., leaking of blood into interstitialspace). Also, the external tensioner may be subject to being dislodgedaccidentally while in use, which may result in complications, such asresumption of bleeding.

In light of the above, it would be desirable to provide alternativedevices, systems, and methods for complete hemostasis of a puncture sitein a body lumen, particularly blood vessels of the human body. It wouldbe particularly desirable if such devices, systems, and methods utilizethe body's own natural healing mechanism to achieve hemostasis. It wouldbe further desirable if such devices and systems utilize a simpleconstruction and user interface allowing for convenient applicationwithout numerous intermediary steps. Further, such devices should bereliable, preserve the integrity of the system, and provide forappropriate tension application without the need for user intervention.At least some of the these objective will be met by the devices,systems, and methods of the present invention described hereinafter.

2. Description of the Background Art

Hemostasis devices for use in blood vessels and tracts in the body aredescribed in co-pending U.S. patent application Ser. Nos. 10/821,633 and10/718,504 and U.S. Pat. Nos. 6,656,207; 6,464,712; 6,056,770;6,056,769; 5,922,009; and 5,782,860, assigned to the assignee of thepresent application. The following U.S. patents and Publications may berelevant to the present invention: U.S. Pat. Nos. 4,744,364; 4,852,568;4,890,612; 5,108,421; 5,171,259; 5,258,000; 5,383,896; 5,419,765;5,454,833; 5,626,601; 5,630,833; 5,634,936; 5,728,134; 5,836,913;5,861,003; 5,868,778; 5,951,583; 5,957,952; 6,017,359; 6,048,358;6,296,657; U.S. Publication Nos. 2002/0133123; 2003/0055454; and2003/0120291.

The full disclosures of each of the above mentioned references areincorporated herein by reference.

BRIEF SUMMARY OF THE INVENTION

The present invention advantageously provides self-tensioning occlusiondevices, systems, and methods for percutaneous access and closure ofpuncture sites in a body lumen, particularly blood vessels of the humanbody. It will be appreciated however that application of the presentinvention is not limited to the blood vasculature, and as such may beapplied to any of the vessels, even severely tortuous vessels, ducts,and cavities found in the body as well as tissue tracts. Such closuredevices, systems, and methods utilize the body's own natural healingmechanism to achieve complete hemostasis without leaving any foreignobjects behind.

In a first aspect of the present invention, a device for hemostasis of apuncture site in a body lumen or tissue tract comprises a catheter bodyhaving a proximal end and a distal end, an occlusion member, and atensioning member. The occlusion member, such as an expansible member,is disposed on a distal end of the body. The tensioning member isslidably disposed over the body and proximal the expansion member.Generally, during application, the tensioning member will bepositionable against subcutaneous tissue so as to lodge and anchor theexpansible member against the puncture site. In particular, theexpansible member allows for sealing of the puncture site while thetensioning member applies and maintains tension to the expansibleoccluder so that it is seated against the puncture site at a vascularsurface (e.g., blood vessel wall).

The present invention integrates the expansible occluder with thetensioning member to form a single unitary catheter construction. Thissimple construction and user interface allows for easy and convenientapplication of the device without numerous intermediary steps. Further,the tensioning member is not subject to interference due to catheterintegration. This results in a more reliable, safe, and effective devicewhich preserves the integrity of the system, which in turn reduces therisk of bleeding, hematoma formation, thrombosis, embolization, and/orinfection, particularly in lengthy applications.

The tensioning member typically comprises a spring or coil of wireformed from a variety of medical grade materials including stainlesssteel, shape memory alloy, superelastic metal, and the like. The wiremay have a diameter in a range from about 0.02 mm to about 1 mm and formany number of loops, typically from 1 to 30 loops. The spring or coildiameter will be in a range from about 1 mm to about 10 mm in a relaxedstate. As discussed in more detail below, the relaxed spring diameter issufficiently large to allow it to be slidably received over the catheterbody and greater than an inner diameter of an introducer sheath. Atubular member may additionally be slidably disposed over the catheterbody and coupleable to a proximal end of the tensioning member. Such atubular member may aid in loading and removal of the tensioning elementas well as provide a mechanism for applying a predetermined amount oradditional tension upon the expansible member.

The expansible member may comprise a variety of structures including abraided filament, mesh layer, spring, coil, slotted tube, or balloon.Generally, a deformable membrane will at least be partially disposedover the expansible member. However, in the case where the expansiblemember comprises a braided mesh, the braid may be sufficiently tightwithout the use of a membrane so that in a deployed state it canadequately occlude the puncture site in the vessel. The expansiblemember may also be coated with a highly hydrophobic coating such asTEFLON® or HYDRO-SIL®. The combination of small pores in the braidedmesh and high surface tension of the expansible member achieved by theuse of such coatings may provide adequate barrier to blood flow throughthe puncture site. Exemplary expansible member structures are describedin detail in co-pending U.S. patent application Ser. No. 10/718,504,assigned to the assignee of the present application and incorporatedherein by reference. The expansible member occludes the vascular surfaceat the puncture site without substantially disturbing the blood flow tothe lower extremities. In some embodiments, the deformable membrane mayfurther comprise a membrane tip at the most distal end of the catheterbody so as to provide a soft and blunt point for percutaneous access. Inother embodiments, a flexible tip deflector may be coupleable to thecatheter body distal the expansible member so as to prevent any damageto the surrounding vessel wall.

The device of the present invention further comprises deployment means,such as a two part handle assembly, coupleable to the proximal end ofthe catheter body. A locking or latching mechanism may be incorporatedinto the two part handle so as to securely and reliably lock theexpansible member in an expanded configuration. Further, such a lockingor latching mechanism may also be incorporated into the tubular memberof the tensioning element so as to provide a connection to thedeployment means for easy loading into the sheath and removal of thetensioning element and the catheter from the body.

In another aspect of the present invention, methods to use the devicefor hemostasis of a puncture site in a blood vessel at an end of atissue tract are provided. A catheter having a proximal end, a distalend, an expansible member at the distal end thereof, and a tensioningmember proximal the expansible member is provided. The catheter isinserted through an opening in a skin surface, typically through a sealof an existing sheath, so as to traverse a length of the sheath andexpose the expansible member of the catheter in a lumen of the bloodvessel. The expansible member of the catheter is then deployed in theblood vessel. The sheath is then slowly pulled out of the body, placingthe expansible member of the catheter against the inner wall of thevessel at the puncture site. As the sheath is further removed, thetensioning member of the catheter which is slidably located on thecatheter shaft is released from the sheath and into the fasciasurrounding the tissue track. The tensioning member is lodged againstthe fascia, providing for adequate tension on the expansible member toseal the puncture site.

Hence, the expansible occluder of the device may be set by the removalof the sheath, therefore simplifying the procedure. Further, thetensioner may be set by the removal of the sheath so as to provide forappropriate tension application. This may be achieved by theinterference between the sheath and the tensioning coil as a result ofthe coil diameter, in a relaxed state, being larger than the sheathdiameter. In other embodiments, the device may be equipped with aloading element, a flexible elongated tube that contains the tensioningelement and can be slidably received within the sheath. In such anembodiment, the tension is set by the interference between thetensioning coil and the loader as the sheath and the loader are removed.When a loader is used, the tension produced and exerted on theexpansible member remains the same. The use of the loader or the sheathto set the tension advantageously eliminates user involvement in settingthe tension, and consequently provides for more precise and consistentapplication of tension. As such, the devices of the present invention donot require measurements, such as length measurements for the placementof the expansible member or force measurements for application oftension. Further, removal of the catheter is simplified, as there is noexternal tensioner to be removed. Generally, the integrated design ofthe present invention greatly simplifies and automates operation of thedevice without any intermediary steps between its application andremoval.

Typically, the amount of tension applied to the expansible member is ina range from about 0.5 ounce to 30 ounces, preferably in a range fromabout 1 ounce to 15 ounces. The expansible member is further anchoredagainst the puncture site. This is typically carried out by thetensioning member. However, in some embodiments, an external clip seatedagainst the skin surface may be utilized to anchor and/or provideadditional tension upon the expansible member. Still further, tension onthe expansible member may be increased by pulling on the tubular membercoupled to the tensioning spring in a proximal direction. It will beappreciated that a predetermined amount of tension may be applied to theexpansible member. For example, the tubular member coupled to thetensioning spring may be displaced a predetermined distance to effect apredetermined transitional tension onto the expansible member.

Deployment of the expansible member typically comprises pushing orpulling a two part handle assembly coupled to the expansible member. Theparts of the handle assembly are locked by conventional mechanicalmeans, so that the expansible member securely remains in a deployedconfiguration. Methods of the present invention may further compriseinterlocking the handle assembly with the tubular member coupled to thetensioning spring. As discussed above, this connection provides for easyloading and removal of the tensioning element and/or for re-introducingthe sheath over the catheter if necessary. Generally, the expansiblemember is deployed to an expanded configuration within the blood vesselhaving a diameter in a range from about 3 mm to about 15 mm.

The expansible member and tensioning member are deployed sequentially orsimultaneously. Deployment of the tensioning member may comprise ofremoving an elongated tubular member, such as an introducer sheath orloading element, disposed over the tensioning member in a proximaldirection. The loading element is preferably removed concurrently withthe sheath. In particular, the diameter of the tensioning member in arelaxed state is greater than the inner diameter of the introducermember so as to provide adequate positioning and tension upon theexpansible member.

The present invention further includes kits comprising a self-tensioningvascular occlusion device as described herein and instructions to usethe device for hemostasis of a puncture site in a blood vessel.Instructions for use will generally recite the steps for performing oneor more of the above described methods. The instructions will often beprinted, optionally being at least in part disposed on packaging. Theinstructions may alternatively comprise a videotape, a CD-ROM or othermachine readable code, a graphical representation, or the like showingany of the above described methods. The kit may further includeadditional components of the system, such as a loading element, sheath,external clip, or the like. The kit components will be packaged in aconventional medical device package that is usually sterile, such as apouch, tray, box, or the like.

A further understanding of the nature and advantages of the presentinvention will become apparent by reference to the remaining portions ofthe specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings should be read with reference to the detaileddescription. Like numbers in different drawings refer to like elements.The drawings, which are not necessarily to scale, illustratively depictembodiments of the present invention and are not intended to limit thescope of the invention.

FIG. 1 illustrates a self-tensioning vascular occlusion device forhemostasis of vascular puncture sites constructed in accordance with theprinciples of the present invention.

FIG. 2 illustrates an alternative embodiment of the occlusion membranethat may be employed in any of the devices disclosed herein.

FIGS. 3A and 3B illustrate another embodiment of the expansible memberin a retracted configuration and an expanded configuration respectivelythat may be employed in any of the devices disclosed herein.

FIGS. 4A and 4B illustrate yet another embodiment of the expansiblemember in a retracted configuration and an expanded configurationrespectively that may be employed in any of the devices disclosedherein.

FIGS. 5A through 5C illustrate an alternative embodiment of thedeployment means that may be employed in any of the devices disclosedherein.

FIG. 6 illustrates a system for hemostasis of a puncture site in a bodylumen employing the device of FIG. 1 in conjunction with a loadingelement.

FIG. 7 illustrates another device for hemostasis of a puncture site in abody lumen employing a locking mechanism.

FIG. 8A though 8D illustrate a method for hemostasis of a puncture sitein a body lumen employing the device of FIG. 1.

FIGS. 9A through 9C illustrate another embodiment of the expansiblemember in a retracted configuration, expanded configuration, andretraction through unwinding process, respectively that may be employedin any of the devices disclosed herein.

FIG. 10 illustrates an exemplary self-tensioning vascular occlusiondevice for hemostasis of vascular puncture sites according to anotherembodiment of the present invention.

FIG. 11 illustrates an alternative embodiment of the occlusion membranethat may be employed in any of the devices disclosed herein.

FIGS. 12A and 12B illustrate the deployment means and the occludingmember of FIG. 10 in a retracted configuration respectively.

FIGS. 13A and 13B illustrate the deployment means and the occludingmember of FIG. 10 in an expanded configuration respectively.

FIGS. 14A through 14C illustrate an alternative embodiment of thedeployment means that may be employed in any of the devices disclosedherein.

FIG. 15A though 15D illustrate a method for hemostasis of a puncturesite in a body lumen employing the device of FIG. 10.

FIG. 16 illustrates the device of FIG. 10 with an integrated dilator forrecovery of vascular access.

FIG. 17 illustrates a non-integrated dilator that may be employed inconjunction with any of the devices disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, a self-tensioning vascular occlusion device 10for hemostasis of vascular puncture sites constructed in accordance withthe principles of the present invention is illustrated. Device 10comprises a first flexible elongated tubular member 11 having a distalend 12 and a proximal end 13. Tubular member 11 may be formed fromcoiled stainless steel tubing or polymer materials such as nylon,polyurethane, polyimide, PEEK®, PEBAX®, and the like. Tubular member 11may have a length in a range from about 10 cm to about 50 cm, preferablyin the range from about 15 cm to about 30 cm and a diameter in the rangefrom about 0.25 mm to about 5 mm, preferably in the range from about 0.5mm to about 2 mm. An expansible occlusion member 14 is disposed on thedistal end 12 of tubular member 11. Further, a tensioning member 26 isslidably disposed over the tubular member 11 and proximal the expansiblemember 14. It will be appreciated that the above depictions are forillustrative purposes only and do not necessarily reflect the actualshape, size, or dimensions of the device 10. This applies to alldepictions hereinafter.

Referring now to FIG. 2, the expansible member 14 may at least partiallyor preferably be fully covered with an elastomeric membrane material 36.Membrane 36 may be formed from a variety of medical grade materials,such as thermoplastic elastomers (e.g., CHRONOPRENE® or POLYBLEND®)having durometers in a range from 15 A to about 40 A. Membrane 36 may beconnected at a distal connection point 17 and a proximal connectionpoint 15. Adhesives such as LOCTITE® 4014 may be used to attach membrane36 to the catheter 11. Alternatively, membrane 36 may take a form of asock having its distal end sealed through a heat stake process or thelike. In this case membrane 36 may not have to be attached distally.Membrane 36 preferably has a diameter that is sufficient to cover theexpansible member 14. In some embodiments, membrane 36 may be designedand attached to facilitate expansible member 14 deployment as well as toreduce the amount of required elongation when the expansible member 14is deployed. This may be achieved by molding the membrane 36 so that itsmidpoint diameter, where deployed expansible member 14 has its greatestdiameter, is larger than its proximal and distal end diameters (e.g., aspherical shape). Membrane 36 may also be formed like a tube with alarger diameter than needed (diameter of retracted expansible member14), and then stretched over expansible member 14 and attached. Thestretch should be enough to reduce the diameter of the membrane 36 tothat of the expansible member 14. In such a case, when member 14 isdeployed, there is less elongation and stress experienced by membrane36. The membrane 36 may additionally form a membrane tip 37 at a distalend 12A of the catheter 11 so as to provide a soft and blunt point forpercutaneous access.

Referring now to FIGS. 3A, 3B, 4A, and 4B, expansible member 14 may beformed from a variety of medical grade materials, including stainlesssteel, superelastic material such as NITINOL®, or polymer materials suchas nylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. Theexpansible member 14 in a retracted or collapsed state has a diameter ofless than about 3 mm, preferably less than about 1.5 mm, as shown inFIGS. 3A and 4A. When deployed, the expansible member 14 in an expandedstate has a diameter in a range from about 3 mm to about 15 mm,preferably from about 4 mm to about 7 mm, as shown in FIGS. 3B and 4B.The expansible member 14 may comprise a push or a pull type deploymentmeans as is described in detail co-pending U.S. patent application Ser.No. 10/821,633, assigned to the assignee of the present application andincorporated herein by reference. Exemplary expansible member structures14 are described in detail in co-pending U.S. patent application Ser.No. 10/718,504, assigned to the assignee of the present application andincorporated herein by reference. Still further embodiments of a braidedmesh member 14 are disclosed in U.S. Pat. No. 5,836,913, alsoincorporated herein by reference.

In a preferred embodiment, the expansible member 14 comprises a pulltype, where the retracted state of the expansible member 14 is itsnatural, unconstrained free state. Deployment of the expansible member14 requires that a member 16 be pulled proximally, as denoted by arrow 9in FIGS. 3A and 4A. FIG. 3A illustrates a malecot member 14 in itsnatural retracted state and FIG. 3B shows this expansible member 14 inits expanded state at a distal end 12B of the catheter 11. FIG. 4Aillustrates another embodiment that comprises a tubular braided meshmember 14 in its free retracted state at a distal end 12C of thecatheter. FIG. 4B illustrates this expansible member 14 in its deployedexpanded configuration. The manner in which these expansible members 14may be assembled onto the catheter 11 and the way in which these members14 may interact with other components of the device 10 are similar.

Referring back to FIG. 1, a proximal end of expansible member 14 isconnected to the distal end 12 of tubular member 11 at connection point15. The connection may be made with a crimp process, use of shrinktubing such as polyester tubing, adhesives such as glue, heat stakingmember 14 into member 11, or a combination thereof. A distal end ofexpansible member 14 is connected to the push/pull member 16 atconnection point 17. Push/pull member 16 may be formed from metals(e.g., stainless steel or NITINOL®) or from polymer materials such asnylon, polyurethane, polyimide, PEEK®, PEBAX®, and the like. Member 16has a diameter small enough to go through the tubular member 11 and alength that is long enough to traverse the length of the tubular member11. The proximal end 13 of members 11 and 16 incorporate a handleassembly 18. A first part of the handle 19 is connected to the proximalend 13 of member 11. A second part of the handle 20 is connected toproximal end of member 16. Handle parts 19 and 20 provide for anenhanced grip on members 11 and 16, allowing the user to moreconveniently move these members with respect to each other for thepurpose of deploying and retracting the expansible member 14. Movingparts 19 and 20 away from each other causes the deployment of expansiblemember 14 and moving them towards each other causes the retraction ofexpansible member 14.

Referring now to FIGS. 5A through 5C, if no friction is built into themovement of members 11 and 16, handle assembly 18A may be designed toallow the deployed state of expansible member 14 to be held in position.This is because the lack of friction allows members 11 and 16 to movefreely with respect to each other forcing the expansible member 14 backto its natural retracted state. Hence, locking features 21 and 22 ofhandle parts 19 and 20 respectively may be locked to maintain theexpansible member 14 in a deployed configuration. In operation, parts 19and 20 are moved apart until features 21 and 22 completely slide overeach other. Handle part 20 can then be twisted with respect to part 19by approximately 180° degrees, allowing the proximal end 21 of handlepart 19 to rest over the distal end 22 of handle part 20, as shown inFIG. 5B. These ends 21 and 22 may be serrated or one end may have a halfcircular protrusion, as in feature 23 on proximal end of part 19, andthe other end have a half circular indentation, such as feature 24 onthe distal end of part 20, allowing these ends to detent into eachother. A top view of this locking mechanism is illustrated in FIG. 5Cshowing the handle assembly in a deployed position. This lockingmechanism may be beneficial to greatly reduce the chances of parts 19and 20 slipping relative to each other causing unintended retraction. Tofurther secure and stabilize the handle assembly 18A, particularlyduring deployment of expansible member 14, a handle housing 35 may atleast be partially disposed over parts 19 or 20. In FIG. 5A, housingmember 35 is attached to the first part of the handle 19 and is longenough that when member 14 is deployed and features 23 and 24 are incontact, member 35 extends proximally beyond feature 22.

Referring now to FIGS. 1, 6, and 7, device 10 also includes a secondflexible tubular member 25 that is slidably disposed over the firsttubular member 11. Second member 25 is formed from a variety of medicalgrade materials, including polymer materials such as nylon,polyurethane, polyimide, PEEK®, PEBAX®, and the like. Second member 25is shorter than first member 11 and may have a length in range fromabout 5 cm to about 40 cm, preferably in the range from about 10 cm toabout 20 cm. A distal end of member 25 is connected to the tension coilspring 26. Tension coil spring 26 comprises a helical coil spring havinga central passage which encompasses first member 11, wherein its distalend is connected to member 11 proximal the expansible member 14 atconnection point 15.

Tensioning member 26 may be formed from a variety of medical gradematerials, including suitable metals such as stainless steel orpreferably shape memory or superelastic metals such as NITINOL®. Theamount of force that expansible member 14 can exert against a vesselwall at the puncture site primarily depends on the diameter of the wireused, the diameter of the resulting coil, the pitch of the coil, and/orthe total number of the loops in the coil of the tensioning member 26.The number of loops in the coil spring 26 may be in the range from about1 loop to about 30 loops, preferably in the range from about 3 loops toabout 20 loops. The coils are preferably wound tightly with little or nopitch between the loops when the coil 26 is at its relaxed state. Thewire diameter used to fabricate the coil 26 may be in the range fromabout 0.02 mm to about 1 mm, preferably in the range from about 0.05 mmto about 0.5 mm. The fabricated coil 26 may have a diameter in the rangefrom about 1 mm to about 10 mm, preferably in the range from about 1.5mm to about 5 mm in a relaxed state. The diameter of the tension coilspring 26 in the preferred embodiment of this invention is chosen to begreater than the inside diameter of an introducer sheath. For example,when a 5 Fr sheath is used the diameter of coil 26 would be greater than1.75 mm. The greater this difference, the greater the interferencebetween the coil spring 26 and the sheath, and consequently the greateris the resulting tension on the expansible member 14 against the vesselwall as the sheath is being removed. The operation of device 10 isdescribed in greater detail below with respect to FIGS. 8A through 8D.

As shown in FIGS. 1, 6, and 7, the distal end 12 of device 10 mayinclude a tip deflector 27. Deflector 27 prevents element 17 fromdamaging the vessel wall on the opposite side of the puncture site. Thismay happen if the user excessively compresses the skin at or adjacent tothe puncture site, which potentially could happen when the device 10 isbeing removed. Deflector 27 may be formed from a variety of medicalgrade materials, including flexible metal coil materials or polymermaterials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®, and thelike. In one embodiment, deflector 27 may be formed from a smalldiameter wire, possibly the extension of member 16, coated with a softpolymer material. Deflector 27 will generally have a diameter equal toor smaller than the catheter diameter at element 17 and a length in therange from about 1 cm to about 10 cm, preferably from about 2 cm toabout 4 cm. A welding process may be utilized to provide for a short andstrong connection point at element 17. It will be appreciated howeverthat the need for a deflector tip 27 may be alleviated if element 17itself is made short and blunt.

Referring now to FIG. 6, device 10 may be equipped with a catheterloading element 28 to facilitate insertion of the device 10 through thesheath when the tensioning member 26 at its relaxed state is larger thanthe inner diameter of the introducer sheath. Loading element 28generally comprises an elongated tubular member 29. An outer diameter ofmember 29 is smaller than the opening in a hub of the sheath and canpenetrate a seal in the sheath. An inner diameter of loader 28 is largeenough to allow the catheter 11 to completely slide through. Loader 28has a length long enough to at least contain all the elements of thecatheter 11 distal to and including the tensioning member 26. Loader 28may include a feature 30 at a proximal end. This feature 30 may be usedas a stop against the hub of the introducer sheath, preventing theloading element 28 from completely sliding into a lumen of the sheath.Loading element 28 may be formed from coiled stainless steel tubing orpolymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®,and the like.

Referring now to FIG. 7, introduction of the device 10A into the sheathand removal of the device 10A from the body may also be facilitated byincorporating a locking mechanism 33 at a proximal end of second tubularmember 25 that may be interlocked with a feature 34 on a distal end ofhandle 19. The locking mechanism 33, 34 allows tensioning member 26 tobe maintained in a stretched state so as to reduce the coil diameter tobelow that of the inner diameter of the introducer sheath and therebyallowing the device 10A to slide through the sheath withoutinterference. In other embodiments, locking features on the catheter 11may interlock with the locking mechanism 33 on member 25. Even whenmember 25 is equipped with an interlocking mechanism 33 so thattensioning member 26 does not interfere with the sheath, loader 28 maystill provide for enhanced introduction of the device 10A into thesheath.

As shown in FIGS. 1, 6, and 7, tubular member 11 has a visual mark 31.When device 10 is inserted through the introducer sheath, alignment ofmark 31 with the opening of the hub of the sheath indicates thatcatheter 10 has been advanced enough through the sheath to expose theexpansible member 14 in the lumen of the vessel. Alternatively, whenelement 30 of loading element 28 is against the hub of the sheath,alignment of mark 31 with the proximal end of feature 30 may indicateappropriate advancement of the expansible member 14 in the vessel lumen.Optionally, alignment of the distal end of handle 19 with the hub of thesheath or loading element 30 may eliminate the need for mark 31. Stillfurther, mechanical means may be utilized for proper location of theexpansible member 14 within the lumen of the vessel.

Referring now to FIGS. 8A through 8D, a method for hemostasis of apuncture site in a body lumen employing the device of FIG. 1 isillustrated. FIG. 8A depicts an existing introducer sheath 40 through anopening in a skin surface 46, tissue tract in fascia 45, and vessel wall43 and seated in a vessel lumen 41 at the completion of acatheterization procedure. Device 10 including loading element 28 isthen inserted through the hub of the sheath 40 so that loading element28 at least penetrates the seal of sheath 40 or until feature 30 isagainst the hub of the sheath 40, as shown in FIG. 8B. Loader 28 may nowbe removed. Alternatively, device 10 with loader 28 present can bepushed into sheath 40 until the identifying mark 31 on member 11 isaligned with feature 30 of loading element 28. As shown in FIG. 8C,expansible member 14 is then deployed by holding part 19 of handleassembly 18A stationary and moving member 20 proximally, as depicted byarrow 8 and described in detail with respect to FIGS. 5A through 5C.Second tubular member 25 may then be pulled proximally until resistanceis felt indicating that expansible member 14 is at the distal end ofsheath 40. If member 25 is equipped with a locking mechanism 33 in alocked position, member 11 or the handle assembly 18A may be grasped topull the device 10 proximally and seat member 14 against the tip of thesheath 40. Member 25 is then unlocked at this point. Optionally, thesheath 40 at the hub may be gently removed from the body so as to seatthe expansible member 14. There may be a short time period of nominalbleeding from when the distal end of the sheath 40 is removed from thevessel lumen 41 and when the expansible member 14 is set against thepuncture site 42.

Referring again to FIG. 8C, once the distal end of sheath 40 exits thevessel wall 43 at puncture site 42 and the expansible member 14 isplaced against the vessel wall 43 at the puncture site 42, theresistance offered by member 14 against the vessel wall 43 will causecatheter 10 to exit the sheath 40. The amount of interference betweentensioning coil 26 and sheath 40 at points 44 determines the amount offorce exerted by member 14 against the vessel wall 43. Overcoming thefriction force between the fascia 45 and the outer surface of sheath 40as well as between the tensioning coil 26 and the sheath 40 at points44, sheath 40 is removed from the body exposing the loops of the coil 26and lodging them into the fascia 45 one loop at a time. Loader 28 alongwith sheath 40 are removed and may be discarded.

Referring now to FIG. 8D, the interference between the loops of the coil26 and fascia 45 provides the hold and retains expansible member 14under tension against the vessel wall 43 at the puncture site 42. Thetension applied to the expansible member 14 is sufficient for completehemostasis, typically in a range from about 0.5 ounce to 30 ounces. Whenthe sheath 40 and/or loader 28 are removed and the coil 26 gets embeddedin the tissue 45, the amount of the tension at the puncture site 42 maydrop as the coil 26 recoils some to engage itself in the tissue 45. Theamount in the reduction of tension is dependant on the tissue type 45surrounding the puncture site 42, the nature of the coil spring 26, andthe thickness of the fascia 45. These factors have been considered inthe proper design of the coil 26 of the present invention.

If greater tension is desired once the device 10 is first seated, secondtubular member 25 may be moved proximally and released increasing theamount of compression that expansible member 14 applies on the vesselwall 43. The increase in the pull force may be limited by the amount ofproximal movement of member 25, which can be determined by the properlength of member 25 and the distance between the proximal end of member25 and distal end of handle part 19. The pull force may be limited byinterference of members 25 and 19. The pull force may also be limited byinterference between the coil 26 and the first tubular member 11. Inparticular, the closer the diameter of member 11 to the inside diameterof coil 26, the less stretch member 26 can experience before the coildiameter is reduced enough to interfere with member 11. In the abovemethodologies, when second member 25 stops moving with respect to firstmember 11, that may be an indication that the maximum allowable and safepull force has been reached.

Device 10 remains in the body for an adequate period of time. Occlusivecompression may be applied proximal to the puncture site 42 when thedevice 10 is to be removed. Expansible member 14 is retracted bymanipulation of handle assembly 18A and member 25 is grasped so as topull the device 10 out of the body. Pulling on member 25 causes coil 26to stretch, reducing the coil diameter, and consequently reducing theamount of interference between coil 26 and fascia 45. If device 10 isequipped with locking features 33 and 34, removal of device 10 may beaccomplished by first pulling on member 25 proximally and interlockingfeatures 33 and 34. This easily disengages device 10 from the fascia 45.Removal of the device 10 may be followed by a few minutes of manualcompression at the skin surface 46 to achieve complete hemostasis.

As shown in FIG. 8D, device 10 may include an external clip 50. Clip 50couples member 25 and rests on the patient's skin surface 46. Clip 50may be used as a safety feature to further secure and keep expansiblemember 14 under tension. It may also be used when greater tension isdesired than that provided by interaction of coil 26 with sheath 40 andfascia 45 alone. In another embodiment (FIG. 10), coil member 26 may beintended to function only as a tensioning member. Coil 26 in thisembodiment may have a diameter smaller than the inner diameter of thesheath 40 and be formed from elastomeric material. This elastomericmember is preferably in a form of a tube which is attached to the firstmember 11 at point 15 and to the distal end of second member 25. Oncethe device is placed in the sheath 40, and expansible member 14 isdeployed, member 25 is used to place expansible member 14 against thevessel wall 43 at the puncture site 42 and to apply the required tensionto the device. The substantial hold once the tension is applied is thenprovided by external means, such as the external clip 50. This devicemay have the advantage of being easier to load and insert through thesheath 40 as the external clip 50 provides anchoring.

Referring now to FIGS. 9A through 9C, a still further embodiment of theexpansible member 60 of the present invention is illustrated. Theexpansible member 60 preferably comprises coiled string constructed fromsmall diameter tubing that is flexible. The tubular configuration mayhave a suture or small diameter wire in its lumen to add to its tensilestrength. Flexible member 60 may be formed from medical grade materials,including polymer materials such as nylon, polyurethane, polyimide,PEEK®, PEBAX®, and the like. Flexible member 60 can be coiled into anexpanded configuration comprising a disc or dome shape 61. Adjacentloops of member 60 may be adhered lightly through a heating or a gluingprocess. Member 60 at the center is fed through a tube 62, wrappedaround tube 62, and is housed in a tubular member 63, as shown in FIG.9A. To deploy the expansible member 60, tube 62 is pushed forward toexpose the expansible member 61. Once extracted from tubular member 63,the expansible member 61 unfolds into a disc or a dome configuration asillustrated in FIG. 9B. The sealing process is attained by pulling ontube 62, allowing the expansible member 61 to press against the puncturesite. Retraction is effected by pulling coil 60 through tube 62, causingthe loops of the expansible member 61 to unwind as depicted by FIG. 9C.Still further embodiments of such an expansible member are disclosed inU.S. patent application No. 2003/0120291, which describes a temporaryseal and method for facilitating anastomosis and is also incorporatedherein by reference.

Referring now to FIGS. 10 through 13B, an exemplary self-tensioningvascular occlusion device 70 for hemostasis of vascular puncture sitesaccording to another embodiment of the present invention is illustrated.Device 70 is similar in many respects to device 10 of FIG. 1 except inregards to the tensioning element. In particular, the tensioning element86 of device 70 comprises a helical coil spring which has a smallerdiameter that applies tension but does not cause its engagement with thesurrounding tissue tract fascia 45, and consequently does not providemeans for maintaining the tension. Tensioning element 86 generally hasan outer diameter that is smaller than that of the introducer sheath 40.The tension is applied by a user grabbing a grip element 85, and pullingthe tensioning element 86 in a proximal direction to achieve hemostasis.The tensioning element 86 in this embodiment provides tension to anexpansible member 74 (similar to expansible member 14). Tension ismaintained by utilization of the external clip 50. Aside from thisdifference mentioned above with respect to the tensioning element 86,the fundamental principles of device 70 remains substantially the sameas device 10.

Tensioning element 86 may be formed from suitable medical grade springcoil materials such as superelastic metals (e.g., NITINOL®) or stainlesssteel. The tensioning element 86 has a diameter in a range from about0.5 mm to about 2.5 mm, preferably from about 0.75 mm to about 1.25 mm.As shown in FIG. 10, an inside diameter of the spring coil 86 is largeenough so that a catheter shaft 71 (similar to tubular member 11) can beslidably received through a lumen of the tensioning element 86. Theoutside diameter of spring coil 86 is smaller than an inside diameter ofthe introducer sheath 40. The tensioning element 86 is sufficiently longenough to extend outside the fascia 45 so that it may be adequatelypulled via the grip element 85 to achieve hemostasis. The length of thetensioning element 86 may be in a range from about 2 cm to about 25 cm,preferably from about 8 cm to about 15 cm. A distal end of thetensioning element 86 is coupled to the catheter shaft 71 at point 75. Aproximal end of tensioning element 86 couples the grip element 85. Thegrip element 85 comprises a tubular member that provides means for theuser to grab the tensioning element 86 and apply consistent tension tothe catheter 71. The grip element 85 may be formed from a variety ofmedical grade materials, including metals or polymer materials such asnylon, polyurethane, polyimide, PEEK®, PEBAX®, polyester and the like.The tubular member 85 is then attached to tensioning element 86 by meansof glue or a heat staking process. The grip element 85 may optionally beformed from shrink tubing materials and attached to the tensioningelement 86 by the application of heat.

Referring now to FIG. 11, the expansible member 74 may at leastpartially or preferably be fully covered with an elastomeric membranematerial 96. Membrane 96 may be formed from a variety of medical gradematerials, such as thermoplastic elastomers (e.g., CHRONOPRENE® orPOLYBLEND®) having durometers in a range from 15 A to about 40 A.Membrane 96 may be connected at a distal connection point 77 and aproximal connection point 75. Adhesives such as LOCTITE® 4014 may beused to attach membrane 96 to the catheter 71. Membrane 96 preferablyhas a diameter that is sufficient to cover the expansible member 74. Themembrane 96 may additionally form a membrane tip 97 at a distal end ofthe catheter 71 so as to provide a soft and blunt point for percutaneousaccess.

Referring now to FIGS. 12A, 12B, 13A, and 13B, a proximal end of thecatheter 70 comprises deployment means 78. FIGS. 12A and 13A illustrateone embodiment of the handle assembly 78. FIGS. 12B and 13B illustratethe corresponding state of the occluding member 74 in a retracted andexpanded configuration respectively. A proximal end of handle assembly78 comprises an actuating assembly 101 which is coupled to a push/pullmember 76 (similar to member 16). Proximal movement of assembly 101relative to a grip handle 102 deploys the expansible member 74. The griphandle 102 comprises a tubular member 103 formed from suitable metaltubing (e.g., stainless steel) or polymer materials (e.g., polyurethane,polyimide, PEEK®, PEBAX®, and the like). Member 103 is coupled to thecatheter shaft 71 by means of an expander element 104 so as to accountfor the difference in an outside diameter of catheter 71 and an insidediameter of member 103. Elements 71, 103, and 104 may be attached by theuse of adhesives. Member 103 further includes a feature 105, such as anindentation from a crimping process when element 103 is formed from astainless steel or other metallic hypotube. Indentation 105 providesinterference to element 106 of the actuating assembly 101.

Actuating assembly 101 further includes a tubular member 107 that isattached to the push/pull member 76 by a crimp process and/or adhesive.Member 107 provides added stiffness to the actuating mechanism 101 aswell as provides for a larger surface area that consequently allows forenhanced adhesion of elements 106, 108, and 109 to member 107. Theseelements may comprise individual, separate parts, preferably formed frompolymer materials such as polyurethane, polyimide, PEEK®, PEBAX®, andthe like. These elements may be optionally incorporated into element 107through an over molding process. Once the device 70 is deployed,interference of detent element 106 with indentation 105 maintains theexpansible member 74 in its deployed position as shown in FIG. 13B. Aproximal end of detent 106 may have a shallow angle in relation to thecatheter shaft 71 so as to provide simplified deployment of theexpansible member 74. A distal end of detent 106 may be moreperpendicular to the catheter shaft 71 so as to provide moreinterference to feature 105, thereby requiring greater force to undeploythe expansible member 74. The increased undeployment force is desirableto avoid inadvertent device collapse. Optionally, indentation 105 may bedesigned so that a distal side of the feature has a much shallower anglein relation to the catheter shaft 71 than a proximal side.

Elements 108 and 109 primarily provide support and alignment of theactuating assembly 101. Element 109 may be formed from a bright distinctcolor to indicate when the expansible member 74 is deployed. Element 110comprises a tubular member, preferably having the same outer diameter asmember 103. A distal end of tubular member 110 abuts a proximal end ofmember 103 so as to provide a positive stop to the movement of theactuating assembly 101 during the undeployment of the expansible member74. Cap 111 at the most proximal end of the device 70 provides a softtip for easier undeployment of expansible member 74. Cap 111 may beformed from rubber or similar materials.

In operation, handle assembly 78 is held by grabbing onto element 103with one hand and element 110 with the other hand. Element 110 is thenpulled in a proximal direction while holding element 103 stationary. Aselement 110 is pulled back, detent 106 slides over indentation 105 untilit is completely moved to the proximal side of feature 105, as seen inFIG. 13A. The interference between elements 105 and 106 keeps theexpansible member 74 in the deployed configuration. Undeployment of thedevice 70 may be effected with a single hand. In particular, member 103may be grabbed by the palm of the hand while the thumb presses on cap111. This causes the actuating mechanism 101 to move forward and thedetent member 106 to slide distally over feature 105, as seen in FIG.12A, resulting in the retraction of the expansible member 74.

An alternative embodiment of the deployment means 120 is illustrated inFIG. 14A though 14C. Handle assembly 120 comprises an actuating assembly121 and a grip handle 122. Grip element 122 comprises a tubular member123 coupled to the catheter shaft 71 by means of an expander element 124to account for the difference in the outside diameter of catheter 71 andan inside diameter of element 123. Tubular member 123 and the expander124 may be formed from suitable metal tubing (e.g., stainless steel) orpolymer materials such as nylon, polyurethane, polyimide, PEEK®, PEBAX®,and the like. Member 123 also includes feature 125. Feature 125 providesinterference to a flaring element 126 of a latching component of theactuating assembly 121.

Actuating assembly 121 includes both a latching component and anunlatching component. The latching component comprises an elongatedtubular element 127 coupled to the push/pull member 76. Feature 128 ofthe latching element provides alignment for sliding the latching elementthrough the handle assembly 120. Feature 128 also prevents excessivepull on the expansible member 74 by abutting feature 125 of the griphandle 122. Feature 129 of the latching element allows for interferencewith the unlatching component of the actuation mechanism 121 when theexpansible member 74 is deployed. The unlatching component of theactuating assembly 121 comprises a tubular member 130 that slidesbetween elements 123 and 126. A proximal end of member 130 is coupled toa cap 131. A coil spring 132 is housed in the cap 131 and rests againstfeature 129 of the latching element.

In operation, grip handle 122 is held stationary at element 123 with onehand while cap 131 is moved in a proximal direction with the other hand.Interference between the unlatching component 130 and feature 129 of thelatching component pulls both components proximally, deployingexpansible member 74 and sliding flare element 126 over feature 125 ofthe grip handle 122. Once the flare element 126 clears the feature 125,flare element 126 expands laterally. Further proximal movement of cap132 is limited by interference of element 128 of the latching componentwith feature 125. Releasing cap 132 results in the flare element 126resting against a proximal end of feature 125 and latching theexpansible member 74 in an expanded state, as shown in FIG. 14B.

Retraction of the expansible member 74 may be effected by pushing cap131 in a distal direction relative to the grip handle 122. Thisoperation may be easily performed single handedly. Pushing cap 131 wouldsimultaneously push the unlatching element 130 and compress and loadcoil spring 132. As element 130 is pushed distally, it slides betweenthe handle element 123 and the flare element 126, causing element 126 tocollapse medially as shown in FIG. 14C. Distal movement continues untila distal end of the flare element 126 clears a proximal end of feature125. Coil spring 132 then distally propels elements 126, 127, 128, and129 along with push/pull member 76, causing the expansible member 74 toretract. Releasing cap 131 places the handle assembly 120 back to anundeployed configuration, as seen in FIG. 14A.

Referring now to FIGS. 15A through 15D, a method for hemostasis of apuncture site in a body lumen employing the device 70 of FIG. 10 isillustrated. FIG. 15A depicts an existing introducer sheath 40 throughan opening in a skin surface 46, tissue tract in fascia 45, and vesselwall 43 and seated in a vessel lumen 41 at the completion of acatheterization procedure. Device 70 is then inserted through the hub ofthe sheath 40 and advanced until the expansible member 74 is outside thesheath 40 and in vessel lumen 41, as shown in FIG. 15B. This positioningmay be indicated by a mark on the catheter 71. Optionally, the device 70may be advanced to a feature on the catheter 71, for example to a distalend of the handle assembly 78. It will be appreciated that a loaderelement is not necessary to the present embodiment as the tensioningelement 86 in its relaxed state has a smaller diameter than the insidediameter of the sheath 40.

As shown in FIG. 15C, the expansible member 74 is then deployed byoperation of the handle assembly 78 as described above. Sheath 40 isthen removed from the body, leaving expansible member 74 seated at thepuncture site 42. In particular, as sheath 40 is removed over thecatheter 71, the grip element 85 is exposed and pulled in a proximaldirection as the sheath 40 is completely removed and discarded. Gripelement 85 is moved proximally to provide an adequate amount of tensionto the deployed expansible member 74 to achieve hemostasis. Typically,the amount of tension applied to the expansible member 74 is in a rangefrom about 0.5 ounce to 30 ounces. The substantial hold once the tensionis applied is then provided by external means. In this case, the thinand small external clip 50 seated against the skin surface 46 maintainstension as seen in FIG. 15D. This device 70 may have the advantage ofbeing easier to load and insert through the sheath 40 as the externalclip 50 provides anchoring.

Referring now to FIG. 16, the device 70 of FIG. 10 with an integrateddilator 150 for recovery of vascular access is illustrated. Inparticular, dilator 150 allows the user to reintroduce the sheath 40over the vascular occlusion device 70 and replace it with the introducersheath 40. Dilator 150 may be located proximal to the expansible member74 and formed from suitable medical grade materials, such as metals(e.g., stainless steel) or preferably polymer materials (e.g., nylon,polyurethane, polyimide, PEEK®, PEBAX®, polyester and the like). Dilator150 may be molded over or glued to the tensioning element 86. Dilator150 may have a length in a range from 0.1 inch to the length of thetensioning element 86, preferably in a range from about 0.25 inch toabout 1.0 inch. Dilator 150 may be flexible and attached at a distal endto the tensioning element 86 so as to preserve the functionality of thetensioning element 86, particularly when dilator 150 is of longerlength. Dilator 150 may have a diameter that accommodates an insidediameter of the sheath 40 or a second catheter to be reintroduced as thediameter of feature 150 defines the size of the sheath to be reinserted.For example, the dilator 150 may have a diameter of about 0.065 inch fora 5 Fr sheath and 0.078 inch for a 6 Fr sheath.

Dilator 150 comprises leading edges 152 and trailing edges 153 which aretapered and a landing 151 therebetween. Leading edges 152 allow for easyintroduction of the introducer sheath 40 through the puncture site 42 inthe vessel wall 43. The trailing edges 153 allow for convenientintroduction of the sheath 40 over the dilator 150. Landing 151 allowsthe user to have some tolerance in locating the introducer sheath 40over the device 70 prior to advancing the sheath 40 into the vessel 41.Hence, recovery of vascular access is facilitated by the dilator 150which provides enhanced column strength to the device 70 and ensuressmooth transition of the sheath 40. Dilator 150 may be positionedanywhere along the length of the tensioning element 86. Preferably, whenthe sheath 40 is placed over the dilator 150, at least a portion of thehandle assembly 78 is exposed through a proximal end of the introducersheath 40.

In operation, the correct sheath size is selected based upon thediameter of the dilator 150. A proximal end of device 70 is insertedinto a distal end of the introducer sheath 40. Device 70 is thenadvanced through the sheath 40 until a proximal end of the device 70penetrates the seal in the hub of the sheath 40 and exits the proximalend of the introducer sheath 40. The sheath 40 is then advanced intoposition so that the distal end of the sheath 40 resides on landing 151.Device 70 is then retracted via manipulation of the handle assembly 78.Following retraction, the sheath 40 and the device 70 are held togetherand advanced distally into the vessel lumen 41. Device 70 is thenremoved, leaving the sheath 40 in the vessel. Hence, device 70 performssimilar in function to a guidewire subsequent to vascular occlusion toallow for recovery of vascular access.

Referring now to FIG. 17, a non-integrated dilator 160 may be employedas an alternative to the integrated dilator 150. Dilator 160 is similarto dilator 150 in that it comprises tapered leading 163 and trailing 164edges with a landing 165 therebetween and is formed from similarmaterials as described above. Dilator 160 further comprises alongitudinal axial slit 162 along a length thereof that is wider thanthe catheter shaft 71 and narrower than the tensioning element 86.Dilator 160 also includes a central longitudinal lumen 161 having adiameter that is larger than that of the grip element 85 but smallerthan a distal end of the device 70 at point 75. Dilator 160 has a lengththat is less than the distance between a distal end of the handleassembly 78 and a proximal end of the grip element 85. Advantageously,dilator 160 may take on any desired diameter so as to allow for theintroduction of a variety of sheaths 40 as the dilator 160 is notintegrated into the device 70.

In operation, the desired diameter of dilator 160 is selected for aparticular sheath size. Dilator 160 is then placed onto the device 70 bysliding the catheter shaft 71 into the slit 162. Dilator 160 is thenpushed forward so that the grip element 85 extends through lumen 161.Dilator 160 is further advanced until it abuts a proximal end of element75. The appropriate sheath 40 is then advanced over device 70 until thedistal end of the sheath 40 is positioned in the landing 165. Device 70is then retracted by manipulation of the handle assembly 78. Followingretraction, the sheath 40 and the device 70 are both advanced into thevessel lumen 41. Device 70 along with the dilator 160 are completelyremoved, leaving the introducer sheath 40 behind in the vessel 41.

Although certain exemplary embodiments and methods have been describedin some detail, for clarity of understanding and by way of example, itwill be apparent from the foregoing disclosure to those skilled in theart that variations, modifications, changes, and adaptations of suchembodiments and methods may be made without departing from the truespirit and scope of the invention. Therefore, the above descriptionshould not be taken as limiting the scope of the invention which isdefined by the appended claims.

1. A system for hemostasis of a puncture site in a body lumen, thesystem comprising: a catheter comprising: (i) a catheter body having aproximal end, a distal end, and at least one axial lumen therethrough;(ii) an occlusion member capable of being radially expanded andcontracted at the distal end of the catheter body; (iii) a helical coilspring having a central passage which receives the catheter body andhaving a distal end fixedly attached to the distal end of the catheterbody and a proximal end having a user grip which allows the user to pullproximally on the coil spring to tension the occlusion member againstthe puncture site; and (iv) an axial member slideably disposed in theaxial lumen of the catheter body to selectively radially expand andcontract the occlusion member; and an external clip coupleable to theproximal end of the coil spring to engage a skin surface in order tohold said proximal end in place over the tissue tract.
 2. The system ofclaim 1, further comprising a sheath disposable at least partially overthe catheter body.
 3. The system of claim 2, wherein a diameter of thecoil spring in a relaxed state is smaller than an inner diameter of thesheath.
 4. The system of claim 1, further comprising a dilatorcoupleable to the catheter body, wherein said dilator provides atransition region for advancing the sheath over the catheter body whilethe catheter is present in a body lumen or tract.
 5. The system of claim4, wherein the dilator is integrally formed with the catheter body so asto form a single component.
 6. The system of claim 4, wherein thedilator has a leading edge, a trailing edge, and a landing therebetween.7. The system of claim 4, wherein the dilator has a length in a rangefrom about 0.25 inch to about 1.0 inch.
 8. The system of claim 7,wherein the dilator has an axial slit along a length thereof.
 9. Thesystem of claim 4, wherein the dilator has a length in a range fromabout 0.25 inch to about 10 inches.